Let's try this. Akar and Brandar are cursed, they lose two point of strength after each long rest, for three long rests.
Two long rests past, and at the start of the third one Brandar has been reduced to zero HPs. The long rest finishes. The curse kicks off, reducing both of their STR by two points. And the curse ends.
What is being argued is that the curse running out is a benefit, so Brandar will suffer then penalty at the end fo the long rest but still have it continue, losing more strength than anyone else even though it was of the same duration.
When really what is happening is that end of a long rest is just when the curse is done.